To prevent abrasion of a cylindrical body fixed to a driven shaft of a vehicular power unit while adopting a structure of loosely fitting the cylindrical body to an inner ring of a bearing.

A collar 56 is fastened to a shaft end of a driven shaft 27 by axially pressing by means of a nut 60 screwed with the shaft end of the driven shaft 27. An inner ring 43a of a bearing 43 is loosely fitted to an outer periphery of the collar 56. A circular elastic body 57 is arranged on the loosely fitting portion.